Figure 1. PSMB5 mutation is not associated with bortezomib (BTZ)-resistant MCL cells.

A. MCL cells (Jeko1 and Mino) and MCL cells with acquired BTZ-resistance (Jeko/BTZ and Mino/BTZ) were incubated with various doses of BTZ for 72 hr. Inhibition of cell growth was measured by the MTT assay. B. BTZ-sensitive cells (Jeko1 and Mino) and BTZ-resistant cells (Jeko1/BTZ and Mino/BTZ) were treated with 10 nM BTZ for 24 hr. Apoptosis was measured by flow cytometry. C. ChT-L activity was measured by fluorescence activity after 24 hr in BTZ (10 nM and 20 nM) -treated or–untreated Jeko1 or Mino cells and their BTZ-resistant cells. D. Expression level of ubiquitin and PSMB5 in Jeko1, Mino, and their BTZ-resistance cells were assessed by Western blotting. β-actin was used as a protein loading control.